means your watch is telling you the time 12 hours too fast. try changing the time a full 12 hours, and then later change the day/date back to the correct one.

Sorry, but basically what ffrozz said.

Your watch is basically 12 hours ahead of the current time. So while it is 9am, the watch thinks it is 9pm. That's why when it comes to noon, it will start to change date, because it's moving into a "new" day. Solution is to simply change the time ahead 12 hours, and then go back and re-adjust your date

reporting in..

Stick to the big box stores like Yodobashi Camera or BIC Camera and you'll be all right. You'll get your tax deduction, and probably some discounts as well

might not get too much luck at Nakano looking for Seiko 5s. they're mainly stocked with Rolexes and the like. Lemon in Ginza might have something.